Malicious Code Exfiltration in codefrequencychecker Package
Summary
MAL-2026-126: Malicious code in codefrequencychecker (PyPI). Affects codefrequencychecker versions 0.0.1 – 0.0.7. No fix is published. How to fix ↓
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Background
The codefrequencychecker package, available on PyPI, is designed to analyze and report on code frequency metrics. However, it has been found to contain malicious code that compromises user data. This vulnerability allows attackers to exfiltrate sensitive information such as browser cookies and passwords, posing a significant risk to users' privacy and security.
Vulnerability Detail
The vulnerability originates from a malicious actor identified as kam193, who has embedded code within the codefrequencychecker package. This code is capable of exfiltrating browser data, including cookies and passwords, and establishes a Telegram bot for ongoing data exfiltration. The malicious intent is clear, as the package functions as an infostealer, utilizing a Telegram webhook to transmit the stolen data. Users who have installed affected versions of the package are at risk of having their sensitive information compromised.
How To Fix
This package is malicious. Remove it and rotate any credentials it could have accessed.
pip uninstall codefrequencycheckerIf it arrived as a transitive dependency, remove the package that pulled it in, then reinstall.
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Workaround
As a temporary workaround, users can avoid using the codefrequencychecker package until a secure version is available. Additionally, users should consider using a virtual environment to isolate their projects and minimize the risk of exposure to malicious packages.
Conclusion
The discovery of malicious code in the codefrequencychecker package highlights the importance of vigilance when using open-source software. Users should take immediate action to protect their data by uninstalling affected versions and monitoring for updates. Utilizing tools like Vulert can help in identifying vulnerabilities in real-time.
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FAQ
Versions 0.0.1, 0.0.2, 0.0.3, 0.0.5, and 0.0.7 of the codefrequencychecker package are known to be affected by this vulnerability.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
If you have installed the affected package, you should uninstall it immediately and refrain from using it until a secure version is released.
The Telegram bot is used by the malicious code to send the exfiltrated data to the attacker, allowing for ongoing data theft.
To protect your sensitive information, regularly update your packages, use trusted sources, and consider employing tools like Vulert to monitor for vulnerabilities in your software.
